1. Technical Field
The present invention concerns a pylon base section for the erection of a wind power installation. The present invention further concerns a pylon base arrangement having a pylon base section. The present invention also concerns a pylon of a wind power installation and a method of erecting a pylon of a wind power installation.
2. Description of the Related Art
Wind power installations are generally known and are frequently erected on a pylon, as is also the case with the wind power installation shown in FIG. 1. Such a pylon of a wind power installation, namely a wind power installation pylon, is erected for that purpose on a suitable foundation. In that case care is also to be taken to provide for perpendicular orientation or levelling of the pylon.
To prepare for erecting a wind power installation pylon it is known for a pylon base section to be partly concreted into the foundation in order to erect the further pylon thereon. Such a pylon base section is in the form of a cylindrical casing or frustoconical casing having an upper peripherally extending annular flange and is concreted into place in such a way that this upper annular flange remains outside the concrete foundation in order to erect the pylon, in particular a steel pylon, thereon. In that case the pylon base section can be held in the aligned or levelled position by a holding device while the concrete foundation is cast. As soon as the concrete has set such a pylon base section can be released from the holding device. Such a method however is intended in particular for smaller pylons and possibly requires later post-levelling on its upper annular flange. Another disadvantage in that respect is that this pylon base section has to be held by the holding device upon pouring and setting of the concrete. That kind of pylon base section can also involve problems in terms of erecting and thus anchoring very large wind power installation pylons.
Another method involves concreting into place a foundation basket having a lower circular segment anchor and a plurality of perpendicular connecting bars arranged in a circular shape, wherein the connecting bars project upwardly from the downwardly disposed segment anchor to which they are connected, through the concrete, and upwardly at the surface of the concrete, where the surface of the concrete or foundation forms a circular fixing region, and the bars are in that case provided with a peripherally extending levelling ring. That levelling ring can be arranged and levelled off after the concrete has set in order to arrange a first pylon segment thereon in properly oriented relationship and to fix it in place. In that arrangement the connecting bars project with threaded portions through corresponding bores in a lower flange of the lower pylon segment and can be provided there with nuts for fixing purposes.
A problem in that respect is that, when pouring the concrete, the connecting bars have to be oriented with a template or jig in the region of the concrete surface or foundation surface to be produced, so that the connecting bars are correctly arranged after the concrete has set and can extend without any problem through the large number of bores in the levelling ring to be arranged, and the flange of the lower pylon segment to be set in place. Such a method is thus complicated and expensive because firstly such a template or jig has to be set in place and, after the concrete has set, has to be replaced by the levelling ring. For that purpose the nut of each connecting bars has to be released to be able to remove the template or jig and then re-fitted after the levelling ring and the lower pylon segment has been set in position. An arrangement with a levelling ring is to be found in German patent application DE 10 2004 017 006 A1.
A problem with that use of a foundation basket with a lower segment anchor and a levelling ring is also that, if the foundation basket is constructed incorrectly or imprecisely, the result can be inclinedly extending connecting bars which can also be referred to as bolts. That can cause problems in further connection of the levelling ring and the first pylon segment to be placed thereon. One cause can involve defective use of an upper template or jig for orienting the bolts.